Rollback Object
Introduction
The Rollback object activity can be used to undo changes (that have not been committed) made to the object in the part of the flow preceding the activity. Furthermore, it deletes objects that have been created but never committed.
Properties
An example of rollback object properties is represented in the image below:
There are two sets of properties for this activity, those in the dialog box on the left, and those in the properties pane on the right.
The rollback object properties pane consists of the following sections:
Action
The Action section of the properties pane shows the action associated with this activity.
You can open a dialog box to configure this action by clicking the ellipsis (…) next to the action.
You can also open the dialog box by double-clicking the activity in the microflow or right-clicking the activity and selecting Properties.
Object
Object defines the object that needs to be rolled back.
Refresh in Client
This setting defines how changes are reflected in the pages presented to the end-user.
Default: No
To make pages of a Mendix app efficient, many widgets display values from an attribute of an object which is cached on the page. Attributes in widgets which use cached data are always reflected in the client even if they are not committed and irrespective of the value of Refresh in client.
If a widget is only updated when a data source is loaded, then rollbacks will only be seen if they are committed and Refresh in client is set to Yes.
When testing your app, ensure that the desired data is being displayed by the widgets you have chosen.
Microflow Is Called from the Client in an Online App
If Refresh in client is set to No, the rollback is not reflected in the client.
If set to Yes, the object is refreshed across the client, which includes reloading the relevant data sources.
Microflow Is Called in an Offline, Native, or Hybrid App
When inside a microflow that is called from an offline, native, or hybrid app, the Refresh in client option is ignored and functions as if it was set to No.
For more information, see the Microflows section of Offline-First Data.
Action Is in a Nanoflow
When inside a nanoflow, the rollback object activity reloads data sources as if Refresh in client was set to Yes.
Common Section
What Does Rollback Do?
A rollback object activity in a microflow or nanoflow is not the same as the rollback option on an Error Event in a microflow.
A rollback from an error event does not trigger any rollback events, and does not reflect whether changes to objects have been committed.
Pressing a Cancel button or triggering a rollback object activity will initiate the rollback events.
- Events:
- All before and after events are executed
- If any before-rollback event returns false, an exception can be thrown
- If an exception occurs during an event, all the applied changes are reverted with the default error handling behavior
- Changes made prior to the rollback are kept
- Database:
- There is no database communication happening during this event unless it is specified in a before- or after-create event
- Result:
- An object with the state Instantiated will be removed, and an object with any other state will be reverted back to the values it had during the last commit
